Dorttocs, As long as you have been using good media, and have stored the burn't product correctly, in a case away from heat and humidity and bright sunlight I see no reason why the media wouldn't last for more than 5 years. I've viewed media I've made 4-5 years ago on less than perfect quality discs and they still play great with no apparent degradation in quality from the time they were originally burn't.
Top of line media with proper storage = at least 5yrs storage time if not more, in my experiences anyways. With Verbatim media, I'd dare say minimum 5 years, probabley quite a few more.